An increase in cases of metastatic prostate cancer has been reported in the United States and researchers suggest that this may be due, in part, to decreases in prostate-specific antigen (PSA), according to epidemiologic data from study presented during Genitourinary Cancer 2021. Symposium.
“To reduce metastatic prostate cancer in the United States, we support policies that encourage shared decisions to maximize PSA screening, such as the updated U.S. Consecration Services Action Group. [USPSTF] instructions, ”study author Vidit Sharma, MD, a senior resident in the Department of Urology at the Mayo Clinic, said at a poster presentation of the data.
PSA screening was found to reduce metastases and mortality in patients with prostate cancer, according to results from an ERSPC randomized trial. However, screening is also known to result in significant injury from overdiagnosis and low-risk prostate cancer recurrence, Sharma noted. As a result, the USPSTGF did not find sufficient evidence to recommend PSA screening in 2008 and went on to recommend it in 2012.
“Several subsequent studies have found an increase in prostate cancer diagnoses from that change,” Sharma said. “While the significance of these studies is that a decrease in PSA screening was due to the increase in metastases, this has not been directly confirmed.”
The aim of this study was to test the hypothesis that a reduction in PSA screening was due to an increased incidence of metastatic prostate cancer at diagnosis. To do this, researchers examined state variability in PSA screening, as well as nationwide variation in the incidence of metastatic disease at the time of diagnosis from 2002 to 2016.
Researchers calculated an age-altered frequency of metastatic prostate cancer diagnosis per 100,000 men from the American Central Cancer Records Association for each state. In addition, survey-weighted PSA screening estimates for men 40 years of age or older were extracted from the Behavioral Risk Factor Monitoring System, which collected data on PSA screening every 2 years since 2002 onwards.
These data were then analyzed in a multi-panel time series by state, using a random effects sequence retrieval model, which looked at random effects at the state level, as well as associated changes in the PSA screening to the incidence of prostate cancer metastasis within and between states.
Results showed a significant difference in the frequency of PSA screening between states in men aged 40 years or older (range, 40.1% –70.3%). However, after 2010, a significant decrease was seen in the median percentage of PSA screening across all states (range, 61.8% –50.5%). In addition, researchers also noted a significant difference in the incidence of age-adjusted metastatic prostate cancer at diagnosis by state (range, 3.3 to 14.3 per 100,000 men) until 2010, when frequency increased moderately across all states.
Researchers found that, with states with a greater reduction in PSA screening, there was a greater increase in the incidence of metastatic prostate cancer at diagnosis. Data from the randomized serial withdrawal model confirmed that reductions in PSA screening were associated with an increase in metastatic disease at diagnosis (1414.9; 95% CI, 12.3–17.5 per 100,000; P. <.01).
“Overall, a difference in PSA screening explained a 27% difference in metastatic disease at diagnosis,” Sharma concluded.
Information
Vidit Sharma, Abhishek Venkataramana, et al. Association of reductions in PSA screening across states with more metastatic prostate cancer in the United States. J Clin Oncol. 2021; 39 (solair 6): 228. doi: 10.1200 / JCO.2021.39.6_suppl.228